| 摘要 |
<P>PROBLEM TO BE SOLVED: To determine either power running or regenerative running with high accuracy without need for complicated computation. <P>SOLUTION: An output current estimation part 50 estimates an output current, and outputs it as an estimated output current value by inputting an input current value detected by a current detector 36 and a gate signal generated by a switching control part 33. The estimated output current value is inputted into a hysteresis comparator 16 through a low-pass filter 15. When the direction from a switching device 37 to an AC reactor 35 is taken as positive in the detection direction of the current detector 36, it is determined as regenerative running if the estimated output current value is positive, and it is determined as power running if negative. <P>COPYRIGHT: (C)2004,JPO |
